Coating agent, plasma-resistant component having coating film formed by the coating agent, plasma processing device provided with the plasma-resistant component

ABSTRACT

With a coating-film-forming coating agent  51  used as a resist including a main component such as cyclorubber-bisazide and a photosensitive component, by immersing deposits  52  deposited on the coating film of the coating agent  51  formed on an in-chamber component  50  in a release liquid such as acetone together with the in-chamber component  50  removed from within a chamber  22,  the deposits  52  attached to the coating film can be removed along with the coating film from the in-chamber component  50  concurrently with the release of the coating film.

FIELD OF THE INVENTION

[0001] The present invention relates to an in-chamber member, a cleaningmethod therefor and a plasma processing apparatus; and moreparticularly, to an in-chamber member to use in the chamber of a plasmaprocessing apparatus in which plasma is excited to carry out a micropatterning process on a surface of a target object to be processed, acleaning method therefor and a plasma processing apparatus provided withsuch an in-chamber member.

BACKGROUND OF THE INVENTION

[0002] In a semiconductor manufacturing process, a micro patterningprocess has conventionally been performed on a surface of an object tobe processed such as a semiconductor wafer by means of, e.g., a plasmaetching apparatus.

[0003] In such a plasma etching apparatus, an upper and a lowerelectrode are installed to face each other in an airtight chamber of aplasma processing vessel thereof. Mounted on the lower electrode is theobject to be processed. When high frequency electric powers are appliedto the upper electrode and the lower electrode, a glow discharge isinduced therebetween. A process gas supplied into the chamber of theplasma processing vessel is converted into plasma by the glow discharge,which enables the object to be patterned by the plasma etching. As theprocess gas, a CF(Fluorocarbon)-based gas has been widely used.

[0004] The plasma processing vessel of the plasma etching apparatus ismade of alumite treated Al(aluminum) employed as a base material.Further, ceramic members made of sintered Al₂O₃(alumina) are detachablymounted on an entire inner surface of the chamber.

[0005] That is, the plasma processing vessel used in the prior artplasma etching apparatus includes an outer wall portion made of Al andan inner wall portion made of the ceramic material of Al₂O₃(alumina),the inner wall portion being detachably mounted on the inner surface ofthe outer wall. Therefore, even in a case where the inner wall portionof the plasma processing vessel is abraded and damaged by plasma,restoration can be achieved by simply replacing the inner wall portionwith a new one.

[0006] Further, in order to perform a desired etching process on theobject in the prior art plasma etching apparatus by effectivelyconfining the plasma between the upper electrode and the lowerelectrode, plasma-resistant members such as a the maintenance of theplasma processing apparatus can be facilitated.┘

[0007] (3) Page 16, line 26 of the Description has been added asfollows:

[0008] ┌therefor.

[0009] Further, since the coating film is separated by immersing thein-chamber member into the peeling solvent and the reaction by-productsabsorbed to the coating film due to the plasma process are removed fromthe in-chamber member together with the coating film that is beingseparated, it is possible to simply and quickly remove the reactionby-products from the in-chamber member of the invention.

[0010] Moreover, since the reaction by-products absorbed to thein-chamber member can be simply and quickly removed by immersing thein-chamber member into the peeling solvent, the maintenance of theplasma processing apparatus of the present invention can befacilitated.┘

[0011] (4) In page 17-1 of the Claims, claims 6 and 7 have been added asin the attached.

[0012] 6. List of Attached Documents

[0013] (1) The description (pages 1, 7, 7-1 and 16-1)

[0014] (2) The Claims (page 17-1) thereon as shown in FIG. 3B, i.e., adeposition state. When such a state is reached, the periodic cleaningwork is performed. The periodic cleaning is carried out by immersing thein-chamber member 60 in a cleaning fluid or a peeling solvent. By onlyimmersing the in-chamber member 60 in the cleaning fluid or the like,however, deposits 61 cannot be completely removed from the in-chambermember 60 and a portion thereof remains as shown in FIG. 3C. For thisreason, it is required to physically remove the residues, e.g., by usinga scoop as shown in FIG. 3D or by blast.

[0015] However, in case where the residues are removed by theabove-explained physical method, the number of processes of the periodiccleaning work increases to that extent, which in turn increases the timeand the cost required for the cleaning work. Furthermore, there mayarise a problem that the in-chamber member 60 is physically damaged. Forthis reason, it may be considered to use rather stronger cleaning fluidand peeling solvent to avoid employing the physical method for removingthe residues. In this case, however, there may arise another problemthat the in-chamber member 60 is chemically damaged, e.g., corroded, dueto the cleaning fluid and the like capable of completely eliminating theresidues.

SUMMARY OF THE INVENTION

[0016] It is, therefore, an object of the present invention to providean in-chamber member to use in the chamber of a plasma processingapparatus, for preventing damage due to plasma; and a cleaning method ofthe in-chamber member, for simply and quickly removing reactionby-products which are absorbed to the in-chamber member during a plasmaprocess.

[0017] In order to achieve the object, the in-chamber member disposed inthe chamber in which the plasma process is carried out includes acoating film to which the reaction by-products generated in the plasmaprocess is absorbed, wherein the coating film is made of a resist and isseparated from the in-chamber member in a peeling solvent.

[0018] Since the in-chamber member includes the coating film made of theresist, the in-chamber member can be prevented from being damaged byplasma, and since the reaction by-products generated in the plasmaprocess are absorbed to the coating film, it is possible to remove thereaction by-products simply and quickly by separating the coating filmfrom the in-chamber member in the peeling solvent.

[0019] Preferably, the coating film may be made of a rest part of theresist except for the photosensitive component.

[0020] Since the coating film of the in-chamber member is made of therest part of the resist except for the photosensitive component, it ispossible to reduce the cost for the formation of the coating film by asmuch as the cost for the photosensitive component, to thereby reduce thecost for the in-chamber member.

[0021] The object is accomplished by a method for cleaning thein-chamber member disposed in the chamber for performing the plasmaprocess and to which the reaction by-products caused by the plasmaprocess are absorbed, the method including the steps of: forming inadvance a coating film made of a resist on a surface of the in-chambermember, and after performing the plasma process, immersing thein-chamber member in a peeling solvent to thereby remove the reactionby-products absorbed to the coating film from the in-chamber membertogether with the coating film that is being separated.

[0022] In accordance with the cleaning method for the in-chamber member,since the reaction by-products which are absorbed to the coating filmdue to the plasma process are removed together with the coating filmwhen the coating film is separated from the in-chamber members immersedin the peeling solvent, it is possible to remove the reactionby-products from the in-chamber member simply and quickly.

[0023] Preferably, the coating film used in the cleaning method for thein-chamber member is made of a rest part of the resist except for thephotosensitive component.

[0024] In accordance with the cleaning method for the in-chamber member,since coating film is made of the rest part of the resist except for thephotosensitive component, it is possible to reduce the cost for thecleaning method by as much as the cost therefor.

[0025] In order to achieve the object, there is provided an in-chambermember to use in the chamber for performing a plasma process, whereinreaction by-products formed on a surface of the in-chamber member areremoved by the cleaning method recited in claim 3 or 4.

[0026] Since a coating film is separated by immersing the in-chambermember into the peeling solvent and the reaction by-products beingabsorbed to the coating film due to a plasma process are removed fromthe in-chamber member together with the coating film that is beingseparated, it is possible to simply and quickly remove the reactionby-products for the in-chamber member.

[0027] In order to achieve the object, there is provided a plasmaprocessing apparatus for micro patterning a surface of an object to beprocessed by exciting plasma in the chamber thereof, wherein the chamberhas therein the in-chamber member of claim 5.

[0028] Since the reaction by-products absorbed to the in-chambercomponent can be simply and quickly removed by immersing the in-chambermember into the peeling solvent, the maintenance of the plasmaprocessing apparatus can be facilitated.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029]FIG. 1 shows an internal structure of a plasma processingapparatus equipped with an in-chamber member in accordance with anembodiment of the present invention;

[0030]FIGS. 2A to 2E present views setting forth states of thein-chamber member to use in the plasma processing apparatus shown inFIG. 1 and a coating film thereof, wherein FIG. 2A depicts thein-chamber member before a coating agent is applied thereon; FIG. 2Boffers the in-chamber member having a coating film formed by applyingthe coating agent thereon; FIG. 2C is a state of the in-chamber memberhaving deposits accumulated on the coating film; FIG. 2D is a state ofseparating the coating film from the in-chamber member shown in FIG. 2C;and FIG. 2E is a a state where the coating film is completely removedfrom the in-chamber member; and

[0031]FIG. 3A to 3E offer views setting forth different states of acleaning work of a conventional in-chamber member, wherein FIG. 3Adepicts a view illustrating a state before the CF-based polymerparticles are deposited on the conventional in-chamber member; FIG. 3Bpresents a view illustrating a state after CF-based polymer particlesare deposited thereon; FIG. 3C represents a state of the conventionalin-chamber member after the cleaning work; and FIG. 3D offers a viewillustrating a physical removing process of residual CF-based polymerparticles.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0032] Hereinafter, a plasma processing apparatus provided within-chamber members in accordance with an embodiment of the presentinvention will be described in detail with reference to the accompanyingdrawings.

[0033]FIG. 1 shows an internal structure of a plasma processingapparatus equipped with in-chamber members in accordance with theembodiment of the present invention.

[0034] A plasma processing vessel 1 of the plasma processing apparatusincludes an outer wall 1 a made of alumite treated Al and an inner wall1 b formed by a ceramic member made of Al₂O₃, the ceramic member beingdetachably provided on an entire inner surface of the outer wall 1 a. Bybeing surrounded with the inner wall 1 b, an airtightly sealed chamber22 (inside of the plasma processing vessel) is formed. In the chamber22, an etching process is performed on a semiconductor wafer which willbe described later.

[0035] In the chamber 22, in-chamber members(plasma-resistant members),e.g., an electrode protection member 8, a discharge ring 12, a focusring 13, an insulation ring 40, a first and a second bellows cover 14,15 and the like, exposed to the plasma environment are installed attheir respective positions.

[0036] Disposed in the plasma processing vessel 1 is a lower electrode 2made of a conductive material. Mounted on a top surface of the lowerelectrode 2 is an electrostatic chuck 4 for adsorbing and maintaining asemiconductor wafer 3 to be processed.

[0037] A bottom surface and a peripheral surface of the lower electrode2 are protected by the electrode protection member 8 which is one of thein-chamber members. A lower surface 8 a and a peripheral surface of theelectrode protection member 8 are covered by a conductive member 9. Theconductive member 9 has an opening 9 b at a central portion of its lowersurface 9 a. Formed at a central portion of the lower surface 8 a of theelectrode protection member 8 exposed through the opening 9 b is anopening 8 b having an opening area smaller than that of the opening 9 bof the conductive member 9. The opening 9 b is provided with atube-shaped member 11 passing therethrough, a leading end thereof beingfixed at the lower surface 8 a of the electrode protection member 8. Thetube-shaped member 11 is made of a conductive material, e.g., oxidizedAl. The tube-shaped member 11 has an opening area larger than that ofthe opening 8 b and the leading end surrounds the opening 8 b. Anelevating shaft 5 is inserted into and passes through both of thetube-shaped member 11 and the opening 8 b of the electrode protectionmember 8. The elevating shaft 5 is movable in a direction indicated byan arrow “A” and a leading end thereof is directly fixed to the bottomsurface of the lower electrode 2. The lower electrode 2 is supported bythe elevating shaft 5. The elevating shaft 5 is connected to a highfrequency power source 7 via a matching unit 6 and serves as a powersupply rod. Interposed between the conductive member 9 and a bottomsurface of the plasma processing vessel 1 is a flexible bellows 10 madeof a conductive material, e.g., stainless steel.

[0038] The discharge ring 12 is fixedly fitted around the peripheralsurface of the electrode protection member 8 in a flange shape. Thefocus ring 13 and the insulation ring 40 are interposed between one endof the electrode protection member 8 and a peripheral surface of theelectrostatic chuck 4. Further, installed at a lower surface of thedischarge ring 12 is a first bellows cover 14 extending downward anderected upward at a bottom surface of the plasma processing vessel 1 isa second bellows cover 15 in such a manner that it overlaps with aportion of the first bellows cover 14.

[0039] Disposed at an upper part of the plasma processing vessel 1 is anupper electrode 16 made of a conductive material facing toward the lowerelectrode 2. The upper electrode 16 is provided with a plurality of gasdischarge through-holes 17. A top surface of the plasma processingvessel 1 is provided with a gas supply inlet 18, which is connected to agas supply source 21 via a mass flow controller 19 and an opening andclosing valve 20. A process gas including a CF(fluorocarbon)-based gasis supplied from the gas supply source 21. Accordingly, the process gasfrom the gas supply source 21 is fed to the gas supply inlet 18 throughthe opening and closing valve 20 and the mass flow controller 19 andthen is introduced into the chamber 22 via the gas dischargethrough-holes 17.

[0040] Provided through bottom surface of the plasma processing vessel 1is a gas exhaust outlet 23 for exhausting the process gas, the gasexhaust outlet 23 being connected to a vacuum pump 24. In addition, anobject transferring port 25 is provided through a lower side wall of theplasma processing vessel 1. The object transferring port 25 is anopening for loading the semiconductor wafer 3 to be processed into thechamber 22 or unloading the processed semiconductor wafer 3 from thechamber 22 therethrough.

[0041] Disposed around an outer circumference of the plasma processingvessel 1 is a permanent magnet 26 for generating a magnetic field alonga direction parallel to a to-be-processed surface of the semiconductorwafer 3 adsorbed to the electrostatic chuck 4.

[0042] In the plasma processing apparatus having such a construction,the position of the semiconductor wafer 3 is controlled by moving theelevating shaft 5 in the direction indicated by the arrow “A” by meansof a driving device(not shown). When a high frequency power of, e.g.,13.56 MHz is applied to the lower electrode 2 from the high frequencypower source 7 via the elevating shaft 5, the glow discharge isgenerated between the lower electrode 2 and the upper electrode 16 tothereby develop an orthogonal electromagnetic field wherein an electricfield and a magnetic field are orthogonal to each other.

[0043] When the chamber 22 is evacuated to a predetermined vacuumatmosphere by the vacuum pump 24 and the process gas from the gas supplysource 21 is fed to the chamber 22 via the gas supply inlet 18, theprocess gas is converted into plasma. Subsequently, the desired micropatterning process is performed on the masked to-be-processed surface ofthe semiconductor wafer 3. At this time, the reaction by-products of thesemiconductor wafer 3 and the CF-based gas, decomposed components andradicals of the CF-based gas generated by the plasma, and the like areproduced and solid particles thereof are dispersed to be absorbed anddeposited on surfaces of the in-chamber members, so that the so-calleddeposits are accumulated on the surfaces of the in-chamber members.

[0044]FIGS. 2A to 2E present views setting forth states of an in-chambermember to use in the plasma processing apparatus shown in FIG. 1 and acoating film thereof, wherein FIG. 2A depicts the in-chamber memberbefore a coating agent is applied thereon; FIG. 2B offers the in-chambermember having a coating film formed by applying the coating agentthereon; FIG. 2C is a state of the in-chamber member having depositsaccumulated on the coating film; FIG. 2D is a state of separating thecoating film from the in-chamber member shown in FIG. 2C; and FIG. 2E isa state where the coating film is completely removed from the in-chambermember.

[0045] In FIG. 2A, there is deposited an in-chamber member 50 after theperiodic cleaning work. Deposits of AlF₃ particles are not left on thein-chamber member 50. As shown in FIG. 2B, a coating agent 51 is appliedon the in-chamber member 50. It is not necessary to apply the coatingagent 51 on an entire in-chamber member 50. The coating agent 51 may beapplied only on a certain portion thereof on which the deposits will beproduced. The source material of the coating agent 51 is a resist usedfor patterning a semiconductor wafer. After the coating agent 51 isapplied on the in-chamber member 50, it is dried to form a coatingfilm(a resist film) thereon.

[0046] Next, a main component and a photosensitive component of theresist and an organic solvent for the dissolution thereof will beexemplified. Cyclized rubber-bisazide, vinyl polycinnamate, naphthalenecompound, phenolic resin, acrylic resin, novolac resin and the like maybe exemplified as the main component. Diazo naphthoquinone compound,aromatic bisazide and the like can be examples of the photosensitivecomponent. The organic solvent may be exemplified by ethyl lactate,ethyl pyruvate, xylene and the like.

[0047] When the etching process is performed in the plasma processingvessel 1, the deposits 52 are accumulated on the coating film of thecoating agent 51 formed on the in-chamber member 50 as shown in FIG. 2C.When the in-chamber member 50 is cleaned by, e.g., the periodic cleaningwork, the in-chamber member 50 disassembled from the chamber 22 isimmersed in a peeling solvent. The peeling solvent is an organic solventsuch as aceton, thinner, alcohols and the like. When the in-chambermember 50 is immersed in the peeling solvent, since the coating agent 51is dissolved by the peeling solvent, the deposits 52 attached to thecoating film of the coating agent 51 are separated from the in-chambermember 50 together with the coating film as shown in FIG. 2D. When thecoating film of the coating agent 51 is separated from the in-chambermember 50, the in-chamber member 50 becomes completely clean as shown inFIG. 2E.

[0048] As described above, in accordance with the preferred embodimentof the present invention, since the coating film of the coating agent 51formed on the in-chamber member 50 can be completely separated byimmersing same in the organic solvent, e.g., acetone, thinner, alcoholand the like, it becomes very convenient. Moreover, since acetone andthe like do not inflict any damage on pure aluminum, the in-chambermember 50 can be used without any concern for being damaged.

[0049] Alternatively, in lieu of the above-explained resist, a rest partof the resist excluding the photosensitive component therefrom may beused as a coating agent, which facilitates treatment of the coatingagent and at the same time reduces the coat therefor.

[Industrial Applicability]

[0050] As described above, since the in-chamber members in accordancewith the present invention include the coating film made of the resist,damage due to plasma can be prevented, and since the reactionby-products originated from the plasma process are absorbed to thecoating film, the reaction by-products can be simply and quickly removedfrom the in-chamber members by separating the coating film from thein-chamber members.

[0051] Further, in case of the in-chamber members having the coatingfilm which is made of the rest part of the resist except for thephotosensitive component, the cost for the formation of the coating filmcan be reduced by as much as the cost for the photosensitive component,thereby reducing the cost for the in-chamber members.

[0052] Moreover, in accordance with the cleaning method for thein-chamber members, since the reaction by-products produced by theplasma process are stuck to the previously formed coating film and thecoating film is separated from the in-chamber members by being immersedin the peeling solvent, the reaction by-products can be easily removedfrom the in-chamber members together with the coating film that is beingseparated.

[0053] Furthermore, in accordance with the cleaning method for thein-chamber members, since the photosensitive component is excluded fromthe resist, the cost for the coating method can be reduced by as much asthe cost therefor.

[0054] Further, since the coating film is separated by immersing thein-chamber member into the peeling solvent and the reaction by-productsabsorbed to the coating film due to the plasma process are removed fromthe in-chamber member together with the coating film that is beingseparated, it is possible to simply and quickly remove the reactionby-products from the in-chamber member of the invention.

[0055] Moreover, since the reaction by-products absorbed to thein-chamber member can be simply and quickly removed by immersing thein-chamber member into the peeling solvent, the maintenance of theplasma processing apparatus of the present invention can be facilitated.

What is claimed is:
 1. (Amended) An in-chamber member to use in thechamber for performing a plasma process, the in-chamber membercomprising: a coating film to which reaction by-products originated fromthe plasma process are absorbed, the coating film being made of a resistand separated from the in-chamber member in a peeling solvent. 2.(Amended) The in-chamber member of claim 1, wherein the coating film ismade of a rest part of the resist except for a photosensitive component.3. (Amended) A method for cleaning an in-chamber member disposed in thechamber for performing a plasma process and on which reactionby-products produced by the plasma process are absorbed, the methodcomprising the steps of: forming in advance a coating film made of aresist on a surface of the in-chamber member; and after performing theplasma process, immersing the in-chamber member into a peeling solventto thereby remove the reaction by-products absorbed to the coating filmfrom the in-chamber member together with the coating film that is beingseparated.
 4. (Amended) The method of claim 3, wherein the coating filmis made of a rest part of the resist except for a photosensitivecomponent.
 5. (Cancelled)
 6. (New) An in-chamber member to use in thechamber for performing a plasma process, wherein reaction by-productsformed on a surface of the in-chamber member is removed by the cleaningmethod recited in claim 3 or
 4. 7. (New) A plasma processing apparatusfor micro patterning a surface of an object to be processed by excitingplasma in a chamber thereof, wherein the chamber has therein thein-chamber member of claim 6.